Light emitting diodes (LEDs) provide a relatively efficient and inexpensive source of light. However, LEDs generally produce light over only a narrow range of visible wavelengths. Thus, to produce white light, the light from multiple LEDs that produce different wavelengths of light can be combined, such that the combination of outputs appears white to a person. Alternatively, the generally-monochromatic light output from an LED can used to pump another light source (e.g., a phosphor material) that absorbs the narrowband light from the LED and emits another, typically broader, spectrum of light, such that the combined spectrum of the LED and the other light source can appear white to a person. The color of light emitted by the LED and the color of light emitted by the pumped light source generally are complementary to each other, so that when the two colors mixed white light results. For example, a blue LED may be used to pump a light source (e.g., a phosphor material) that emits yellow light, because blue and yellow are complementary colors.
LEDs that are used to produce white light can be used to provide backlighting for a liquid crystal display (LCD) device.